After I (and possibly others) reported the previous error message to Microsoft in September 2012, they seem (in December 2012) to have made a correction to the error message. It now allows the possibility that the user may be using Internet Explorer 10, but in compatibility mode. However, what the error message omits to say is that this is unlikely to have been a choice made by the user. Instead, it seems to be Microsoft who have set things up so that IE10 automatically opens intranet sites (which the Office 365 site seems to be treated as) in compatibility mode. So shouldn't Microsoft either remove the message for users with IE10, or change the default setting so that the Office 365 site is not opened by default in compatibility mode?